The disclosure of Japanese Patent Application No. 2002-155656 filed on May 29, 2002, including the specification, drawings and abstract, is incorporated herein by reference in its entirety.
1. Field of the Invention
The invention relates to method and apparatus for controlling a diesel engine, in which an injected fuel quantity reduction process for preventing black smoke is executed based on the engine speed, and an injected fuel quantity reduction process for preventing shift shock during shifting of an automatic transmission is executed.
2. Description of Related Art
There is known a process in which a shift control system of a diesel engine causes an engine control system to reduce the injected fuel quantity during shifting so as to temporarily reduce the engine output torque, thereby avoiding or suppressing shift shock in the automatic transmission, as disclosed in Japanese Laid-open Patent Publication No. 5-71385, for example.
In the meantime, when the engine speed of the diesel engine suddenly increases, black smoke may be generated due to unstable combustion in the diesel engine. In view of this problem, the engine control system is adapted to temporarily reduce the injected fuel quantity so as to suppress or limit black smoke when the engine speed increases at a greater rate than a threshold value provided for preventing black smoke.
In the combination of the shift control system and the engine control system as described above, however, the following problem may occur: when the shift control system executes a shifting process, in particular, when the shift control system performs power-on downshifting, the engine speed suddenly increases, which may cause the engine control system to perform the injected fuel quantity reduction process for preventing black smoke as described above.
As described above, the shift control system operates to reduce the output torque of the diesel engine for preventing shift shock, and also perform switching of the combination of rotary members to be engaged or connected within the automatic transmission at a suitable point of time selected in accordance with the reduction of the engine output torque. Thus, the shift control system performs a series of these operations, thereby to prevent or reduce torque variations at the output shaft of the automatic transmission during shifting.
However, if the injected fuel quantity is reduced during shifting for the purpose of preventing black smoke, independently of shift control, the engine output torque may be reduced to such an extent that is not expected by the shift control system. In this case, the shift control system is not able to expect rotating conditions of the respective rotary elements within the automatic transmission, and cannot perform switching of the combination of the rotary members to be engaged in the transmission at a suitable point of time or in suitable timing. In this situation, the shift control system may not be able to desirably prevent torque variations at the output shaft of the automatic transmission.
It is therefore an object of the invention to provide method and apparatus for controlling a diesel engine that is arranged to perform an injected fuel quantity reduction process for preventing black smoke and an injected fuel quantity reduction process for preventing shift shock, wherein the effect of preventing shift shock is not influenced or disturbed by the injected fuel quantity reduction process for black smoke prevention.
To accomplish the above object, there is provided according to a first aspect of the invention a method of controlling a diesel engine that performs an injected fuel quantity reduction process for preventing black smoke based on an engine speed, and performs an injected fuel quantity reduction process for preventing shift shock during shifting of an automatic transmission, which method comprises the step of inhibiting the injected fuel quantity reduction process for preventing black smoke during shifting of the automatic transmission.
With the method as described above, the injected fuel quantity reduction process for preventing black smoke is inhibited during shifting of the automatic transmission, and therefore reduction of the engine output torque, which is not expected by a shift control system, does not occur during shifting. Accordingly, when the automatic transmission is shifted up or down by switching the combination of rotary members to be engaged in the transmission at a suitable point of time that is determined in accordance with the injected fuel quantity reduction process for preventing shift shock, shift shock can be surely avoided or suppressed since the rotary members in the transmission are placed in rotating conditions expected by the shift control system. Thus, in the diesel engine that is arranged to perform the injected fuel quantity process for preventing black smoke and perform the injected fuel quantity process for preventing shift shock of the automatic transmission, the effect of preventing shift shock is not affected by the injected fuel quantity process for preventing black smoke.
Since the injected fuel quantity reduction process for preventing black smoke is inhibited temporarily, namely, only during shifting, the inhibition has a little influence on the effect of black smoke prevention. Furthermore, since the injected fuel quantity reduction process for preventing shift shock is performed during shifting, black smoke is likely to be suppressed even if the injected fuel quantity reduction process for preventing black smoke is inhibited, thus causing almost no problem associated with black smoke prevention.
According to a second aspect of the invention, there is provided a method of controlling a diesel engine that performs an injected fuel quantity reduction process for preventing black smoke based on an engine speed, and performs an injected fuel quantity reduction process for preventing shift shock during shifting of an automatic transmission, which method comprises the step of reducing an amount of reduction of an injected fuel quantity in the injected fuel quantity reduction process for preventing black smoke during shifting of the automatic transmission.
Instead of inhibiting the injected fuel quantity reduction process for preventing black smoke, the amount of reduction of the injected fuel quantity for preventing black smoke may be reduced during shifting of the automatic transmission. With this arrangement, even if the injected fuel quantity reduction process for preventing black smoke is executed during shifting, reduction of the engine output torque, which is not expected by the shift control system, is less likely to occur during shifting. Accordingly, when the automatic transmission is shifted up or down by switching the combination of rotary members to be engaged in the transmission at a suitable point of time that is determined in accordance with the injected fuel quantity reduction process for preventing shift shock, shift shock can be surely avoided or suppressed since the rotary members in the transmission are substantially placed in rotating conditions expected by the shift control system. Thus, in the diesel engine that is arranged to perform the injected fuel quantity process for preventing black smoke and perform the injected fuel quantity process for preventing shift shock of the automatic transmission, the effect of preventing shift shock is not affected by the injected fuel quantity process for preventing black smoke.
The amount of reduction of the injected fuel quantity for preventing black smoke is corrected to be reduced temporarily, namely, only during shifting, and the injected fuel quantity reduction process for preventing black smoke is not completely inhibited. Thus, since the injected fuel quantity may be reduced for preventing black smoke though a degree of the reduction is less than normal, the reducing correction has little influence on the effect of preventing black smoke. Furthermore, the injected fuel quantity reduction process for preventing shift shock is performed during shifting, and therefore black smoke is likely to be suppressed even if the amount of reduction of the injected fuel quantity for preventing black smoke is reduced, thus causing almost no problem associated with black smoke prevention.
According to a third aspect of the invention, there is provided a method of controlling a diesel engine that performs an injected fuel quantity reduction process for preventing black smoke based on an engine speed, and performs an injected fuel quantity reduction process for preventing shift shock during shifting of an automatic transmission, which method comprises the step of inhibiting the injected fuel quantity reduction process for preventing black smoke during execution of the injected fuel quantity reduction process for preventing shift shock.
The injected fuel quantity reduction process for preventing black smoke may be inhibited during execution of the injected fuel quantity reduction process for preventing shift shock. If the injected fuel quantity reduction process for preventing black smoke, in which the injected fuel quantity is reduced by a relatively large degree, is executed during execution of the injected fuel quantity reduction process for preventing shift shock, the conditions of the rotary members within the automatic transmission may become greatly different from those as expected by the shift control system, and the effect of preventing shift shock may be affected to a large extent. According to the third aspect of the invention, the injected fuel quantity reduction process for preventing black smoke is inhibited particularly during execution of the injected fuel quantity reduction process for preventing shift shock, and therefore the effect of preventing shift shock will not be largely affected or reduced.
Since the injected fuel quantity reduction process for preventing black smoke is inhibited temporarily, namely, only during execution of the injected fuel quantity reduction process for preventing shift shock, the inhibition has a very little influence on the effect of black smoke prevention. Furthermore, since the injected fuel quantity reduction process for preventing shift shock is performed during the period of the inhibition, black smoke is likely to be suppressed even if the injected fuel quantity reduction process for preventing black smoke is inhibited, thus causing almost no problem associated with black smoke prevention. In addition, since the injected fuel quantity reduction process for preventing black can be executed based on the engine speed unless the injected fuel quantity reduction process for preventing shift shock is executed, the effect of preventing black smoke is further improved.
According to a fourth aspect of the invention, there is provided a method of controlling a diesel engine that performs an injected fuel quantity reduction process for preventing black smoke based on an engine speed, and performs an injected fuel quantity reduction process for preventing shift shock during shifting of an automatic transmission, which comprises the step of restricting reduction of an injected fuel quantity in the injected fuel quantity reduction process for preventing black smoke during execution of the injected fuel quantity reduction process for preventing shift shock, based on an amount of reduction of the injected fuel quantity in the injected fuel quantity reduction process for preventing shift shock.
During execution of the injected fuel quantity reduction process for preventing shift shock, the injected fuel quantity reduction process for preventing black smoke is not inhibited, but reduction of the injected fuel quantity for preventing black smoke may be restricted based on the amount of reduction of the injected fuel quantity for preventing shift shock.
With this arrangement, even if the injected fuel quantity reduction process for preventing black smoke is executed during execution of the injected fuel quantity reduction process for preventing shift shock, reduction of the engine output torque, which is not expected by the shift control system, can be restricted. Accordingly, when the automatic transmission is shifted up or down by switching the combination of rotary members to be engaged within the transmission at a point of time that is determined in accordance with the injected fuel quantity reduction process for preventing shift shock, shift shock can be surely avoided or suppressed since the rotary members in the automatic transmission are substantially placed in rotating conditions expected by the shift control system. Thus, in the diesel engine that is arranged to perform the injected fuel quantity process for preventing black smoke and perform the injected fuel quantity process for preventing shift shock of the automatic transmission, the effect of preventing shift shock is not affected by the injected fuel quantity process for preventing black smoke.
The reduction of the injected fuel quantity for preventing black smoke is restricted temporarily, namely, only during execution of the injected fuel quantity reduction process for preventing shift shock, and the injected fuel quantity reduction process for preventing black smoke is not completely inhibited. Thus, since the injected fuel quantity may be reduced for preventing black smoke though a degree of the reduction is less than normal, the restriction on the reduction of the injected fuel quantity has a very little influence on the effect of preventing black smoke. Furthermore, the injected fuel quantity reduction process for preventing shift shock is performed during the period of the restriction, and therefore black smoke is likely to be suppressed even if the reduction of the injected fuel quantity for preventing black smoke is restricted, thus causing almost no problem associated with black smoke prevention.
According to a fifth aspect of the invention, there is provided a method of controlling a diesel engine that performs an injected fuel quantity reduction process for preventing black smoke based on an engine speed, and performs an injected fuel quantity reduction process for preventing shift shock during shifting of an automatic transmission, which method comprises the step of reducing an amount of reduction of an injected fuel quantity in the injected fuel quantity reduction process for preventing black smoke during execution of the injected fuel quantity reduction process for preventing shift shock.
During execution of the injected fuel quantity reduction process for preventing shift shock, the injected fuel quantity reduction process for preventing black smoke is not inhibited, but the amount of reduction of the injected fuel quantity for preventing black smoke may be corrected to be reduced.
With this arrangement, even if the injected fuel quantity reduction process for preventing black smoke is executed during execution of the injected fuel quantity reduction process for preventing shift shock, reduction of the engine output torque, which is not expected by the shift control system, can be restricted. Accordingly, when the automatic transmission is shifted up or down by switching the combination of rotary members to be engaged within the transmission at a point of time that is determined in accordance with the injected fuel quantity reduction process for preventing shift shock, shift shock can be surely avoided or suppressed since the rotary members in the transmission are substantially placed in suitable rotating conditions expected by the shift control system. Thus, in the diesel engine that is arranged to perform the injected fuel quantity process for preventing black smoke and perform the injected fuel quantity process for preventing shift shock of the automatic transmission, the effect of preventing shift shock is not affected by the injected fuel quantity process for preventing black smoke.
The amount of reduction of the injected fuel quantity for preventing black smoke is corrected to be reduced temporarily, namely, only during execution of the injected fuel quantity reduction process for preventing shift shock, and the injected fuel quantity reduction process for preventing black smoke is not completely inhibited. Thus, since the injected fuel quantity may be reduced for preventing black smoke though a degree of the reduction is less than normal, the reducing correction has a very little influence on the effect of preventing black smoke. Furthermore, the injected fuel quantity reduction process for preventing shift shock is performed during the control as described above, black smoke is likely to be suppressed even if the amount of reduction of the injected fuel quantity for preventing black smoke is corrected to be reduced, thus causing almost no problem associated with black smoke prevention.
In the diesel engine control method according to any one of the first through fifth aspects of the invention, each of the injected fuel quantity reduction process for preventing black smoke and the injected fuel quantity reduction process for preventing shift shock may include the step of setting an upper limit value of the injected fuel quantity, and the method may further comprise the steps of: (a) selecting a smaller one of the upper limit value set in the injected fuel quantity process for preventing black smoke and the upper limit value set in the injected fuel quantity process for preventing shift shock, and (b) limiting the injected fuel quantity based on the selected upper limit value.
While each of the injected fuel quantity reduction process for preventing black smoke and the injected fuel quantity reduction process for preventing shift shock may be performed by directly reducing the calculated injected fuel quantity for correction, the calculated injected fuel quantity may be corrected to be reduced by setting the upper limit value of the injected fuel quantity, and selecting the smaller one of the upper limit values set by the respective injected fuel quantity reduction processes so as to restrict the injected fuel quantity.
According to a sixth aspect of the invention, there is provided a method of controlling a diesel engine that performs an injected fuel quantity reduction process for preventing black smoke based on an engine speed, and performs an injected fuel quantity reduction process for preventing shift shock during shifting of an automatic transmission, wherein each of the injected fuel quantity reduction process for preventing black smoke and the injected fuel quantity reduction process for preventing shift shock comprises setting an upper limit value of an injected fuel quantity. This method comprises the steps of: (a) selecting a smaller one of the upper limit value set in the injected fuel quantity process for preventing black smoke and the upper limit value set in the injected fuel quantity process for preventing shift shock, (b) limiting the injected fuel quantity based on the selected upper limit value; and (c) increasing the selected upper limit value for correction when a shift of the automatic transmission is in progress and the injected fuel quantity reduction process for preventing black smoke is being executed.
When the injected fuel quantity for preventing black smoke is executed during shifting of the automatic transmission, the selected upper limit value is corrected to be increased so that the amount of reduction of the injected fuel quantity for preventing black smoke is substantially corrected to be reduced. The control method according to the sixth aspect of the invention provides similar effects to those provided by the control method according to the second aspect of the invention.
According to a seventh aspect of the invention, there is provided a method of controlling a diesel engine that performs an injected fuel quantity reduction process for preventing black smoke based on an engine speed, and performs an injected fuel quantity reduction process for preventing shift shock during shifting of an automatic transmission, wherein each of the injected fuel quantity reduction process for preventing black smoke and the injected fuel quantity reduction process for preventing shift shock comprises setting an upper limit value of an injected fuel quantity. This method comprises the steps of: (a) selecting a smaller one of the upper limit value set in the injected fuel quantity process for preventing black smoke and the upper limit value set in the injected fuel quantity process for preventing shift shock; (b) limiting the injected fuel quantity based on the selected upper limit value; and (c) increasing the selected upper limit value for correction when the injected fuel quantity reduction process for preventing shift shock and the injected fuel quantity reduction process for preventing black smoke are both being executed.
When both of the injected fuel quantity reduction process for preventing shift shock and the injected fuel quantity reduction process for preventing black smoke are being executed, the selected upper limit value is corrected to be increased so that the amount of reduction of the injected fuel quantity for preventing black smoke can be substantially corrected to be reduced. The control method according to the seventh aspect of the invention provides similar effects to those provided by the control method according to the fifth aspect of the invention.
According to an eighth aspect of the invention, there is provided a diesel engine control apparatus, comprising: (a) an engine speed detector that detects an engine speed of a diesel engine, (b) a black smoke preventing unit that performs reduction of an injected fuel quantity for preventing black smoke when an amount of change of the engine speed detected by the engine speed detector is larger than a threshold value set for preventing black smoke; (c) a shift control unit that controls a shift of an automatic transmission, (d) a shift shock preventing unit that performs reduction of the injected fuel quantity for preventing shift shock during shifting of the automatic transmission under control of the shift control unit, and (e) an inhibiting unit that inhibits the reduction of the injected fuel quantity by the black smoke preventing unit when a shift of the automatic transmission is in progress under control of the shift control unit.
Since the inhibiting unit inhibits the reduction of the injected fuel quantity by the black smoke preventing unit when a shift of the automatic transmission is in progress under control of the shift control unit, reduction of the engine output torque, which is not expected by the shift control unit, does not occur during shifting. Accordingly, when the automatic transmission is shifted up or down by switching the combination of rotary members to be engaged in the transmission at a point of time that is determined in accordance with the injected fuel quantity reduction process for preventing shift shock, shift shock can be surely avoided or suppressed since the rotary members in the transmission are placed in rotating conditions expected by the shift control unit. Thus, in the diesel engine including the black smoke preventing unit and the shift shock preventing unit, the effect of preventing shift shock is not affected by the operation of the black smoke preventing unit.
Since the inhibiting unit inhibits the injected fuel quantity reduction process for preventing black smoke temporarily, namely, only during shifting, the inhibition has a little influence on the effect of black smoke prevention. Furthermore, since the shift shock preventing unit reduces the injected fuel quantity for preventing shift shock during shifting, black smoke is likely to be suppressed even if the reduction of the injected fuel quantity by the black smoke preventing unit is inhibited, thus causing almost no problem associated with black smoke prevention.
According to a ninth aspect of the invention, there is provided a diesel engine control apparatus, comprising: (a) an engine speed detector that detects an engine speed of a diesel engine, (b) a black smoke preventing unit that performs reduction of an injected fuel quantity for preventing black smoke when an amount of change of the engine speed detected by the engine speed detector is larger than a threshold value set for preventing black smoke, (c) a shift control unit that controls a shift of an automatic transmission, (d) a shift shock preventing unit that performs reduction of the injected fuel quantity for preventing shift shock during shifting of the automatic transmission under control of the shift control unit, and (e) a reduction amount reducing unit that reduces an amount of reduction of the injected fuel quantity by the black smoke preventing unit when a shift of the automatic transmission is in progress under control of the shift control unit.
Since the reduction amount reducing unit reduces the amount of reduction of the injected fuel quantity by the black smoke preventing unit during shifting of the automatic transmission under control of the shift control unit, reduction of the engine output torque, which is not expected by the shift control unit, is less likely to occur during shifting. Accordingly, when the automatic transmission is shifted up or down by switching the combination of rotary members to be engaged within the transmission at a point of time that is determined in accordance with the injected fuel quantity reduction process for preventing shift shock, shift shock can be surely avoided or suppressed since the rotary members in the transmission are substantially placed in rotating conditions expected by the shift control unit. Thus, in the diesel engine including the black smoke preventing unit and the shift shock preventing unit, the effect of preventing shift shock by the shift shock preventing unit is not affected by the injected fuel quantity process for preventing black smoke.
The reduction amount reducing unit reduces the amount of reduction of the injected fuel quantity for preventing black smoke temporarily, namely, only during shifting, and the injected fuel quantity reduction process for preventing black smoke is not completely inhibited. Thus, since the black smoke preventing unit performs reduction of the injected fuel quantity for preventing black smoke though a degree of the reduction is less than normal, the control as described above has a very little influence on the effect of preventing black smoke. Furthermore, the shift shock preventing unit performs reduction of the injected fuel quantity for preventing shift shock during shifting, and therefore black smoke is likely to be suppressed even if the amount of reduction of the injected fuel quantity by the black smoke preventing unit is corrected to be reduced, thus causing almost no problem associated with black smoke prevention.
According to a tenth aspect of the invention, there is provided a diesel engine control apparatus, comprising: (a) an engine speed detector that detects an engine speed of a diesel engine, (b) a black smoke preventing unit that performs reduction of an injected fuel quantity for preventing black smoke when an amount of change of the engine speed detected by the engine speed detector is larger than a threshold value set for preventing black smoke, (c) a shift control unit that controls a shift of an automatic transmission, (d) a shift shock preventing unit that performs reduction of the injected fuel quantity for preventing shift shock during shifting of the automatic transmission under control of the shift control unit, and (e) an inhibiting unit that inhibits the reduction of the injected fuel quantity by the black smoke preventing unit while the shift shock preventing unit is executing the reduction of the injected fuel quantity.
In the apparatus as described above, the inhibiting unit inhibits reduction of the injected fuel quantity by the black smoke preventing unit while the shift shock preventing unit is executing reduction of the injected fuel quantity. If the injected fuel quantity reduction process for preventing black smoke, in which the injected fuel quantity is reduced by a relatively large degree, is executed during execution of the injected fuel quantity reduction process for preventing shift shock, the effect of preventing shift shock may be affected to a large extent. According to the tenth aspect of the invention, the reduction of the injected fuel quantity by the black smoke preventing unit is inhibited particularly during reduction of the injected fuel quantity by the shift shock preventing unit. This arrangement makes it possible to avoid or suppress reduction of the engine output torque, which is not expected by the shift control unit, during a period in which the reduction of the injected fuel quantity for preventing black smoke has a particularly large influence on the operation of the shift control unit. Thus, shift shock can be surely avoided or suppressed. In the diesel engine including the black smoke preventing unit and the shift shock preventing unit, the effect of preventing shift shock by the shift shock preventing unit is not affected by the black smoke preventing unit.
Since the inhibiting unit inhibits the injected fuel quantity reduction process for preventing black smoke temporarily, namely, only during execution of the injected fuel quantity reduction process by the shift shock preventing unit, the inhibition has a little influence on the effect of black smoke prevention. Furthermore, since the shift shock preventing unit performs reduction of the injected fuel quantity during the period of the inhibition, black smoke is likely to be suppressed even if the injected fuel quantity reduction by the black smoke preventing unit is inhibited, thus causing almost no problem associated with black smoke prevention. In addition, since the black smoke preventing unit is able to execute the injected fuel quantity reduction process for preventing black smoke unless the shift shock preventing unit executes reduction of the injected fuel quantity, the effect of preventing black smoke is further improved.
According to an eleventh aspect of the invention, there is provided a diesel engine control apparatus, comprising: (a) an engine speed detector that detects an engine speed of a diesel engine, (b) a black smoke preventing unit that performs reduction of an injected fuel quantity for preventing black smoke when an amount of change of the engine speed detected by the engine speed detector is larger than a threshold value set for preventing black smoke, (c) a shift control unit that controls a shift of an automatic transmission, (d) a shift shock preventing unit that performs reduction of the injected fuel quantity for preventing shift shock during shifting of the automatic transmission under control of the shift control unit, and (e) a reduction amount restricting unit that restricts an amount of reduction of the injected fuel quantity by the black smoke preventing unit during execution of the reduction of the injected fuel quantity by the shift shock preventing unit, based on an amount of reduction of the injected fuel quantity by the shift shock preventing unit.
During execution of the injected fuel quantity reduction process by the shift shock preventing unit, the injected fuel quantity reduction process by the black smoke preventing unit is not inhibited, but the restricting unit may restrict the amount of reduction of the injected fuel quantity for preventing black smoke, based on the amount of reduction of the injected fuel quantity by the shift shock preventing unit.
With this arrangement, even if the injected fuel quantity reduction process by the black smoke preventing unit is executed during execution of the injected fuel quantity reduction process by the shift shock preventing unit, reduction of the engine output torque, which is not expected by the shift control unit, can be restricted, whereby shift shock can be avoided or suppressed. Thus, in the diesel engine including the black smoke preventing unit and the shift shock preventing unit, the effect of preventing shift shock is not affected by the injected fuel quantity process for preventing black smoke.
The amount of reduction of the injected fuel quantity by the black smoke preventing unit is restricted temporarily, namely, only during execution of the injected fuel quantity reduction process by the shift shock preventing unit, and the injected fuel quantity reduction by the black smoke preventing unit is not completely inhibited. Thus, since the injected fuel quantity may be reduced for preventing black smoke though a degree of the reduction is less than normal, the restriction on the amount of reduction of the injected fuel quantity has a very little influence on the effect of preventing black smoke. Furthermore, since the injected fuel quantity reduction by the shift shock preventing unit is performed during the period of restriction, black smoke is likely to be suppressed even if the amount of reduction of the injected fuel quantity for preventing black smoke is restricted, thus causing almost no problem associated with black smoke prevention.
According to a twelfth aspect of the invention, there is provided a diesel engine control apparatus, comprising: (a) an engine speed detector that detects an engine speed of a diesel engine, (b) a black smoke preventing unit that performs reduction of an injected fuel quantity for preventing black smoke when an amount of change of the engine speed detected by the engine speed detector is larger than a threshold value set for preventing black smoke, (c) a shift control unit that controls a shift of an automatic transmission, (d) a shift shock preventing unit that performs reduction of the injected fuel quantity for preventing shift shock during shifting of the automatic transmission under control of the shift control unit, and (e) a reduction amount reducing unit that reduces an amount of reduction of the injected fuel quantity by the black smoke preventing unit, during execution of the reduction of the injected fuel quantity by the shift shock preventing unit.
In the apparatus as described above, even if the injected fuel quantity reduction process by the black smoke preventing unit is executed during execution of the fuel quantity reduction process by the shift shock preventing unit, reduction of the engine output torque, which is not expected by the shift control unit, can be restricted, whereby shift shock can be avoided or suppressed. Thus, in the diesel engine including the black smoke preventing unit and the shift shock preventing unit, the effect of preventing shift shock by the shift shock preventing unit is not affected by the injected fuel quantity reduction process by the black smoke preventing unit.
The amount of reduction of the injected fuel quantity by the black smoke preventing unit is corrected to be reduced temporarily, namely, only during execution of the injected fuel quantity reduction process by the shift shock preventing unit, and the injected fuel quantity reduction by the black smoke preventing unit is not completely inhibited. Thus, since the injected fuel quantity may be reduced for preventing black smoke though a degree of the reduction is less than normal, the control as described above has a very little influence on the effect of preventing black smoke. Furthermore, the injected fuel quantity reduction process by the shift shock preventing unit is performed during the control as described above, and therefore black smoke is likely to be suppressed even if the amount of reduction of the injected fuel quantity by the black smoke preventing unit is corrected to be reduced, thus causing almost no problem associated with black smoke prevention.
In the diesel engine control apparatus according to any one of the eighth through twelfth aspects of the invention, each of the black smoke preventing unit and the shift shock preventing unit may perform reduction of the injected fuel quantity by setting an upper limit value of the injected fuel quantity. This apparatus may further include a restricting unit that selects a smaller one of the upper limit value set by the black smoke preventing unit and the upper limit value set by the shift shock preventing unit, and restricts the injected fuel quantity based on the selected upper limit value.
While each of the black smoke preventing unit and the shift shock preventing unit may directly reduce the calculated injected fuel quantity for correction, the calculated injected fuel quantity may be corrected to be reduced by setting the upper limit value of the injected fuel quantity, and causing the restricting unit to select the smaller one of the upper limit values set by the black smoke preventing unit and the shift shock preventing unit so as to restrict the injected fuel quantity.
According to a thirteenth aspect of the invention, there is provided a diesel engine control apparatus, comprising: (a) an engine speed detector that detects an engine speed of a diesel engine, (b) a black smoke preventing unit that performs reduction of an injected fuel quantity for preventing black smoke by setting an upper limit value of the injected fuel quantity when an amount of change of the engine speed detected by the engine speed detector is larger than a threshold value set for preventing black smoke, (c) a shift control unit that controls a shift of an automatic transmission, (d) a shift shock preventing unit that performs reduction of the injected fuel quantity for preventing shift shock by setting an upper limit value of the injected fuel quantity, during shifting of the automatic transmission under control of the shift control unit, (e) a restricting unit that selects a smaller one of the upper limit value set by the black smoke preventing unit and the upper limit value set by the shift shock preventing unit, and restricts the injected fuel quantity based on the selected upper limit value, and (f) a reduction amount reducing unit that reduces an amount of reduction of the injected fuel quantity for preventing black smoke by increasing the upper limit value selected by the restricting unit when a shift of the automatic transmission is in progress under control of the shift control unit and the black smoke preventing unit is executing the reduction of the injected fuel quantity.
When the injected fuel quantity reduction by the black smoke preventing unit is executed during shifting of the automatic transmission, the reduction amount reducing unit increases the selected upper limit value so that the amount of reduction of the injected fuel quantity for preventing black smoke is substantially reduced. The control apparatus according to the thirteenth aspect of the invention provides similar effects to those provided by the control apparatus according to the ninth aspect of the invention.
According to a fourteenth aspect of the invention, there is provided a diesel engine control apparatus, comprising: (a) an engine speed detector that detects an engine speed of a diesel engine, (b) a black smoke preventing unit that performs reduction of an injected fuel quantity for preventing black smoke by setting an upper limit value of the injected fuel quantity when an amount of change of the engine speed detected by the engine speed detector is larger than a threshold value set for preventing black smoke, (c) a shift control unit that controls a shift of an automatic transmission, (d) a shift shock preventing unit that performs reduction of the injected fuel quantity for preventing shift shock by setting an upper limit value of the injected fuel quantity, during shifting of the automatic transmission under control of the shift control unit, (e) a restricting unit that selects a smaller one of the upper limit value set by the black smoke preventing unit and the upper limit value set by the shift shock preventing unit, and restricts the injected fuel quantity based on the selected upper limit value, and (f) a reduction amount reducing unit that reduces an amount of reduction of the injected fuel quantity for preventing black smoke by increasing the upper limit value selected by the restricting unit when both the shift shock preventing unit and the black smoke preventing unit are executing the reduction of the injected fuel quantity.
When both of the shift shock preventing unit and the black smoke preventing unit execute reduction of the injected fuel quantity, the reduction amount reducing unit increases the upper limit value selected by the restricting unit so that the amount of reduction of the injected fuel quantity for preventing black smoke is substantially reduced. The control apparatus according to the fourteenth aspect of the invention provides similar effects to those provided by the control apparatus according to the twelfth aspect of the invention.